Global Temperature Just Short of Record in September, Says NOAA

By: Jeff Masters and Bob Henson , 10:25 PM GMT on October 18, 2016

September 2016 was Earth's second warmest September since record keeping began in 1880, said NOAA's National Centers for Environmental Information (NCEI) on Tuesday. In the NOAA database, September 2016 came in 0.89°C (1.66°F) warmer than the 20th-century average for September, and just 0.04°C shy of the record set in September 2015. NASA reported the warmest September in its database, with September 2016 a mere 0.01°C above the previous record, set in September 2014.

September 2016 marked the end of a remarkable streak of 16 consecutive months in which NOAA’s global monthly temperature record was broken, the longest such streak since global temperature records began in 1880. Ocean-only temperatures this September were 0.04°C (0.07°F) cooler than the record warmth of September 2015, while land-only temperatures were 0.11°C (0.20°F) above the previous land-only record from September 2015. (Since most of Earth’s surface is covered by ocean, the land-plus-ocean reading is dominated by the ocean-only temperatures, thus keeping September 2016 just short of the land-plus-ocean record) For the lowest 8 km of the atmosphere, global satellite-measured temperatures in September 2016 were tied for warmest with 1998 for any September in the 38-year record, according to the University of Alabama in Huntsville (UAH).

With the powerful 2015-16 El Niño event having ended early in 2016, the impressive global warmth in recent months can mostly be attributed to the steady build-up of heat-trapping greenhouse gases due to human activities. NOAA’s global surface temperature for the year so far (January-September 2016) is an eye-opening 0.78°C (1.40°F) above the 20th-century average and 0.08°C (0.14°F) warmer than the previous January-to-September record, set in 2015 (see Figure 2 below).

Temperatures would have to plummet at an almost unthinkable pace between now and December in order to keep 2016 from becoming the warmest year in global record-keeping.

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